The present invention relates generally to aircraft flight data collection and more particularly to collection of data useful in accident and incident investigations.
Many commercial and some military aircraft carry flight data recorders (FDRs) and cockpit voice recorders (CVRs). The flight data recorder receives encoded data from a variety of onboard sensors that monitor aircraft performance and stores this data in a form that may be retrieved later. The cockpit voice recorder records verbal exchanges between the crew and ground controllers as well as ambient cockpit noise.
The FDR and CVR, also known colloquially as xe2x80x9cblack boxes,xe2x80x9d have played a significant role in determining the particular cause of aircraft accidents and providing data to assist in the prevention of similar accidents. The FDR and CVR normally comprise a recording medium housed in a crash survivable enclosure. The recording medium may be magnetic tape, optical disc, or in most modern aircraft, a semiconductor memory device. The data stored on these devices enables investigators to reconstruct the last minutes of flight, the events leading to the accident and the responses made by the crew.
As critical as the information recorded on the flight data recorders and flight data recorders is to accident investigation, these devices still may not capture all the data useful for analyzing an accident scenario. Vital information regarding the cockpit environment, non-verbal crew communications, crew workload, instrument display selections and status has not been available on traditional data and voice recorders. This limitation has curbed the scope of many investigations, but more importantly, has hindered the identification of safety issues and consequently the corrective action needed to prevent future occurrences. In several high profile accident investigations, despite the availability of state of the art flight data and cockpit voice recorder systems, the official findings of the investigation have generated considerable controversial debate reducing the time and energy that could have been better used on safety improvements.
For example, the position of certain cockpit switches, or the reading on certain cockpit gauges, may not always be determined with certainty because the particular switch/gauge position is not a parameter recorded by the FDR. Thus, accident investigators are forced to reconstruct the cockpit instrumentation from the accident wreckage to determine the switch/gauge position at the time of the accident. However, this method leads to uncertainty since the force of the accident impact could itself be responsible for positioning the gauge or switch in the recovered position. Alternatively, accident investigators analyze the ambient noises and crew communications recorded on the CVR for any audible indications that a particular switch was set or gauge reading announced.
The above example is but one example of the many types of data that investigators must infer from the recovered recorded data. Simply adding more instrumentation and recording additional parameters is not a practical option. Anticipating which of the multitude of parameters not already recorded will be relevant to an accident scenario cannot be done in advance. In addition, data recorders, of whatever type, will always have some finite capacity, thereby necessitating choices in what parameters to record.
One solution proposed is to strategically position video cameras throughout the aircraft to obtain visual images of the aircraft and crew operations during flight. U.S. Pat. Nos. 6,009,356; 5,974,349; 5,890,079; 5,742,336 and 4,816,828 each disclose an aircraft safety system that includes video cameras for monitoring aircraft operations. Video cameras have the advantage of providing a visual record of events and eliminate the need to reconstruct those events from other indirect evidence. However, the presence of video cameras aboard the aircraft raises privacy concerns among flight professionals and the flying public. Since these systems continuously record data, pilots"" and flight attendants"" unions and passenger activist groups have been reluctant to accept the presence of video cameras onboard the aircraft. Thus, the safety advantages possible from analyzing video data have not yet been realized.
In addition, video data consumes a significant quantity of bandwidth, or system storage memory. Continuously recording all video data onto a FDR or CVR memory device is simply not practicable. In part for this reason, the systems described in the aforementioned US Patents also downlink continuous video data via satellite telemetry systems to remote ground stations for storage. Such systems raise additional privacy concerns since, unlike the onboard storage systems which are overwritten, the ground based storage architecture enables archiving of information. Furthermore, the downlinking and transmission of data from the aircraft is an expensive process which adds significantly to the cost of aircraft operations.
The present invention recognizes the safety advantages possible through use of aircraft video image data. The present invention additionally recognizes and solves the privacy, capacity and cost issues not recognized or solved by prior art systems incorporating video data. The present invention augments existing flight and voice data by capturing images of the flight deck and other aircraft locations to better understand the cockpit environment, flight crew interactions and the overall human/machine interface. The present invention also enables the capture of information that is otherwise impractical to explicitly record on the FDR and/or CVR.
According to one aspect of the present invention, an event based video image recording system is used to collect video data. Various parameters may be pre-identified to determine when activation of the video data recording system occurs. Upon occurrence of one or more of these predetermined parameters, the video data recording system activates and stores the video data in an FDR, CVR or other memory device. Optionally, once the system is activated, the video data may be downlinked using the aircraft onboard ACARS system or other telemetry device.
According to another aspect of the present invention, video cameras are placed at strategic locations throughout the aircraft where video information is likely to prove of use in analyzing crash or incident events. Such locations may include for example: the aircraft cockpit, the cargo holds and passenger cabins. Locations may also include locations on the exterior of the aircraft.
According to yet another aspect of the present invention, the predefined criteria for activating video recordings at individual ones of the many strategic locations may be different for each of the locations. Furthermore, the criteria may be user defined, using for example, a reconfigurable algorithmic network that may be used to logically associate various data parameters with data gathering/recording activities to be performed.
Further aspects and advantages of the present invention will be described in greater detail below.